1. Field of the Invention
The present invention relates to an aqueous suspended agricultural chemical composition having high preservation stability, which contains ethyl(R)-2-[4-(6-chloroquinoxalin-2-yloxy)phenoxy]propionate.
2. Description of the Related Art
Ethyl(R)-2-[4-(6-chloroquinoxalin-2-yloxy)phenoxy]propionate (hereinafter referred to as quizalofop-p-ethyl) is known to have two kinds of crystal forms. One is a low melting point type crystal (hereinafter referred to as α-type crystal) and the other is a high melting point type crystal (hereinafter referred to as β-type crystal) (see Japanese Patent Examined Publication No. Hei 4-76721).
Although quizalofop-p-ethyl has heretofore been handled as an emulsion, there is a demand for a highly safe aqueous suspended composition free of organic solvents (flowable agent). However when the aqueous suspended composition having been prepared with industrially produced α-type crystal quizalofop-p-ethyl particles is stored under severe condition, at 50° C. for 30 days, after the preparation, a phenomenon wherein flowability of this aqueous suspended composition deteriorates during the storage is sometimes observed. Therefore there has been a demand for the further improvement of the preservation stability the aqueous suspended composition.